Electric organ crescendo system



Aug. 2, 1966 D. R. KERN ELECTRIC ORGAN CRESCENDO SYSTEM Original Filed NOV. 2l, 1960 FDRCLJO Wd a mllw.

United States Patent O 3,264,398 ELECTREC ORGAN CRESCENDO SYSTEM Donald R. Kern, Chicago, lll., assignor to Hammond Organ Company, Chicago, Ill., a corporation of Delaware Continuation of application Ser. No. 70,511, Nov. 21, 1960. rThis application Mar. 26, 1964, Ser. No. 358,137

4 Claims. (Cl. 84-1.2'7)

The present invention relates to the electrical musical instrument art, and more particularly to a crescendo systern suitable for use in electric organs.

This application is a continuation of copending application Serial No. 70,511, tiled November 21, 1960, now abandoned.

One of the objects of the present invention is to supply `a novel system in an electric organ which provides a true crescendo effect as opposed to a mere increase in volume.

An additional object is to accomplish the -above in a novel manner at relatively low cost and with a minimum of complexity.

Yet another object is to provide a novel crescendo system which is particularly adapted for use with electric organs of the type in which the desired tone coloration is synthesized by combining fundamental tones with other simple and complex tones which bear a musical relationship to the fundamental.

Other objects and advantages will become apparent from the following description of a preferred embodiment of my invention which is illustrated in the accompanying drawings.

In the drawings, the single ligure is an electrica-l circuit diagram illustrating the crescendo system of the present invention as applied to the pertinent portion of the circuitry of an electric organ.

The crescendo effect which is available in most of the better pi-pe organ installations varies from organ to organ, but in general consists in providing a control which has the eliect of gradually bringing into operation all, or substantially all, of the pipes which are capable of sounding the notes being played. This causes the organ to speak progressive-ly louder and with a voice which becomes progressively more complex with the additive effect of the strings, reeds, diapason, Woodwinds, and in general whatever is available among the organ resources. This progressively increasing complexity of the tone coloration along with an increase in volume is extremely effective and highly expressive for certain purposes.

It is this overall effect that the circuitry of the present invention adds to an electric organ, particularly a tone synthesizing organ of the general character of that which forms the subject matter of Patent No. 1,956,350, issued to Laurens Hammond on April 24, 1934. Since only a portion of the circuitry of such an organ is involved in applying the present invention, the complete organ has not been illustrated, and reference is made to the beforementioned patent for any portion of the organ structure and organization which may be unfamiliar.

Near the left hand edge of the drawing there is shown a section of the keyboard, thirteen bus bars 21, and two preset keys 2t) and 22. A portion of the circuit which is not shown, but which may be considered as conventional and which is described in the beforementioned patent, operates whenever keys :are played to connect the fundamentals and various octave-ly or otherwise musically related tone signals individually to the keyboard bus bars 21. Preset key 22, when depressed, connects the keyboard lbus -bars 21 via leads 2S to establish any desired relative output signal level by connecting them to selected bus bars on preset panel 24 as connected for preset panel 28. To connect bus bars 21 in the same order to a group of leads 26 which, in turn, are connected individually to slides *or draw bars of .preset panel` 28, preset key 20 is depressed. These draw bars can be `arranged to connect any one of the leads 26 to any one of a group of bus bars 30 which are essentially the equivalent of the bus bars comprising the preset panel 24 and which are wired in parallel therewith, as will appear presently.

In the specific example given, the draw bars of preset panel 28 have numbers applied individually thereto, these numbers being in succession from 1 to 13 inclusive. The tone signals applied to these draw bars from the keyboard -bus bars 21 -are as follows:

The last three of these-that is, 11, 12 and -13--are harmonic mixtures, and differ from the others in that they are not simple, essentially eine wave tones, but are tones which have a complex wave form of the type, -for instance, typically obtained from organ tone generators of the electronic oscillator variety. Their purpose, when used, is to add -a rich harmonic structure to the synthetically organized basic tone so that the organ has the advantages of both the synthetic type and of the type in which cornplex tones are used as electronically generated or as moditied by formant circuits.

When the draw bars of preset panel 28 4are all in the off position-that is, in the positions shown in the ligure- `bars 1, 2 and 3 engage a bus indicated by the numeral 32. Similarly, draw bars 4 to 10 inclusive engage bus bar 34, while draw bars 11, 12 and 13 engage bu-s bar 36, In the next more 4advanced position, all of the draw bars 1 to 10 inclusive engage bus bar 38, while draw bars 11, 12 and 13 similarly engage bus bar 40. Successive more advanced bus bar positions in the group 1 'to 10 inclusive are indicated in order by the numerals 42, 46, 5l), 54, 58, 62 and 66. The similar additional bus bars in more -advanced order for the draw bars 11, 12 and 13 are indicated by the numerals 44, 48, 52, 56, 60, 64 and 68.

The bus bars for the draw bars 11, 12 and 13 are connected individually to a similar set of bus bars arranged in the group at 24 which function with the preset key switches, similar to key 22, which makes the illustrated connections to the leads indicated at 25. Similarly the bus bars which make contact with the draw bars in the group numbered -from 1 to 10 inclusive are connected individually to a similar set of bus bars in the preset panel 24, and one additional bus bar in this group, indicated at 70, is grounded and is connected by lead 72 to the short bus bar 32 which is in the oil position of the draw bars 1, 2 and 3.

To the right of the portion of the circuit just described is shown a pair of sequenced gang switches with each of the individual switches in the gangs being of the single pole, double throw type. The lower gange is indicated `generally by the numeral 74 and is made up of seven switches. Each of these switches has a shiftable contact blade, these members being indicated from the bottom bythe numerals 76, 78, 80, 82, 84, 86 and 88. When in the at rest condition, each of these switch blades engages a stationary contact thereabove, these stationary contacts being indicated by the same numeral as is applied to the switch blade with the subscript a so that switch blade 76 normally engages switch contact 76a, and so on. When the switch blades are shifted to their other alternative positions, each is separated from its a contact and engages a similar stationary contact indicated by the subscript b. The switches are so arranged that they make and break simultaneously, or as closely thereto as possible, and in so far as this action is not simultaneous it should be of the make before break type.

The switch gangs are operated by a crescendo pedal 89 in such fashion that as the pedal is slightly moved to introduce the crescendo effect, the first switch 76 is actuated from the a to the b position. With additional movement, switch 78 is shifted from the a to the b position, and so on until finally all of the switches have been shifted from the a to the b connections.

The second gang switch, indicated generally by the numeral 90, may be considered as identical to the switch 74 and is actuated by the same pedal 89 or other crescendo control. In this switch the movable blades are indicated from the bottom in order by the numerals 92, 94, 96, 98, 100, 102 and 104. As with the previous -gang switch, each of the blades e-ngages, -when at rest, a contact having the same number as the blade but with the subscript a, whereas the alternatively used contacts bear the subscript b. These switches are also actuated in sequence in the same order as the gang at 74 and approximately simultaneously therewith, so that as the crescendo pedal is depressed and as the position is reached at which switch blade 76 is shifted from the a to the b position, switch 92 will also be shifted from its a to its b position, and so on.

A preamplifier input transformer is indicated at 110, the secondary 112 thereof being connected to supply the input signal to the boxed circuit at 114 which may be conventional and which 'in the present instance performs the following functions. In this section the signal is preamplified, is controlled by the swell pedal, hasvibrato introduced if desired, its overall volume is regulated between loud and soft positions, and there may be a balance control so as to proportion the amplitude of the signal leaving this section to that of other portions of the instrument. From the section 114 (the circuits of which are usually collectively referred to as a preamplifier) the signal is introduced by way of .leads 116 to a conventional power amplifier which supplies conventional speakers in a well known manner, this portion of the circuit therefore not being illustrated in detail.

A similar transformer at 118 has a secondary 120 which supplies a signal to a harmonic mixture preamplifier indicated generally by the numeral 122. In this boxed portion of the circuit the signal is preamplified, swell controlled, tone controlled, balanced, and its overall volume is regulated much in the manner of the preamplifier at 114. As in the previous example also, the output of the circuit 122 is supplied to leads 124 which are connected to the input of a suitable power amplifier and speaker system which may be the same as that supplied bythe other preamplifier 114.

Other tonal effects not having to do specifically with the present invention, such as percussion for instance, and exemplified by the box 125, may be introduced by way of the lead 126 connected through a resistor 128 to the ungrounded side of the transformer secondary 120 which supplies the harmonic mixture preamplifier 122.

The transformer 110 has a tapped primary, indicated generally by the numeral 130, which is grounded at one end and which has eight successive taps or terminals above the ground level, including the terminal at the opposite end of the primary, these taps (beginning at the one next above ground) being indicated in order by the numerals 132, 134, 136, 138, 140, 142, 144 and 146. Because of the low impedance of this winding, it acts similar to atapped resistor so that if a signal is connected between ground and the first tap 132, such a signal will produce a weak response in the secondary 112, Whereas if the same signal is connected between ground and the second tap 134, a stronger secondary signal will be produced, and so on, the strongest signal being produced in the .secondary and hence in the output when the input is connected between ground and the opposite end terminal of the primary indicated by the numeral 146.

The transformer at 118 has substantially the identical arrangement, the terminals of the primary 148 thereof in succession above ground being indicated in order by the numerals 150, 152, 154, 156, 158, 160, 162 and 164.

As with the transformer at 110, connecting a signal between ground and successively higher taps on the primary of the transformer 148 has the effect of progressively increasing the signal strength in the transformer secondary 120, and hence in the preamplifier and output.

Connections to the transformer primary are as follows: The bottom tap is grounded and is connected by lead 170 to ground the stationary switch contact 76a. The first tap 132 is connected by lead 172 to contact 78a. Similarly tap 134 is connected by lead 174 to switch contact 80a. Lead 176 connects contact 82a with tap 136; lead 178 interconnects contact 84a and tap 138; lead 180 is connected between contact 86a and tap 140; contact 88a is connected by lead 182 to tap 142; lead 184 connects tap 144 to contact 88b and by way of a branch 186 these connections are extended to bus bar 62 of the draw bar assembly. The top end of the transformer 146 is connected by lead 188 to the bus bar 66.

Movable switch contact 88 is connected by lead 190 to stationary contact 86h and by a branch 192 to bus bar 58. Similarly, switch blade 86 is connected by lead 194 to switch contact 84h and by a branch 196 to bus bar 54. Switch contact 84 is connected by lead 198 to switch contact 82b and by branch 200 to bus bar 50. Lead 202 interconnects switch contacts 82 and 80b, and a branch 204 thereof leads to bus bar 46. Lead 206 interconnects switch contacts 80 and 78b, and a branch 208 leads to bus bar 42. Lead 210 interconnects switch contacts 78 and 76b, and a branch 212 of this lead is connected to bus bar 38. The lowermost movable contact 76 is connected by .line 214 to bus bar 34. Although not specically mentioned above, each of the bus bar leads 188, 186, 192, 196, 200, 204, 208, 212 and 214 is connected by an appropriate branch, these branches being indicated generally by the numeral 216 to the appropriate bus bar in the preset panel at 24.

In a similar manner, the grounded end of the transformer primary 148 is connected by lead 218 to switch contact 92a, whereas lead 220 interconnects transformer tap 150 and switch contact 94a; lead 222 interconnects tap 152 and contact 96a; lead 224 interconnects tap 154 and contact 98a; lead 226 interconnects tap 156 and contact 100a; 228 connects tap 158 to contact 102a; 230 connects tap to contact 104a; 232 connects tap 162 to contact 104b, and a branch 234 thereof connects to bus bar 64. The top end of the transformer 164 is connected by lead 236 to bus bar 68. Additionally, contact =104 is connected to contact 102b by lead 238 having a branch 240 leading to bus bar 60. Contact 102 is connected to contact 100b by lead 242 having a branch 244 leading to bus bar 56. Lead 246 interconnects contacts `100 and 98b, and a branch 248 thereof leads to bus bar 52.` Lead 250 having a branch 252 interconnects contacts 98 and 96b and bus bar 48. Lead 254 having a branch 256 interconnects contacts 96 and 94b and bus bar 44. Lead 258 having a branch 260 interconnects contacts 94 and '92b and bus bar 40. The lowermost movable contact 92 is connected by lead 262 to bus bar 36. As in the the numeral 264 to the similar bus bars in the. preset panel at 24.

The system operates as follows. When any one of the draw bars from 1 to 13 is all the way in, or in other words in its off position, no sound for its particular frequency will be apparent in the music played upon the instrument. For example, bus bar 34 is connected by lead 214 and by way of switch 76-76a to ground through line 170. Changes in the potential of this bus bar, therefore, do not produce any current in the transformer primary. Also bus bar 36 is connected by lead 262 and switch contacts 92 and 92a to ground through lead 218. Bus bar 32, it should be noted, is connected directly to ground by lead 72 without any intervening switch c-ontacts. This is done because it is sometimes not desirable to have the subfrequencies, represented in this embodiment by draw bars 1, 2 and 3, enter into the crescendo effect. inasmuch as these three draw bars are always grounded when they are in their innermost positions, these three s-ubfrequencies do n-ot sound during the crescendo. If it is desired to have any or all of the subfrequencies participate in the crescendo, it lis necessary merely to move the appropriate draw bar 1, 2 or 3 int-o the second or some position other than its completely in (or off) position. All the other draw bars, however, are grounded when in the off position by way of switch contacts which can subsequently be broken, as will be explained, so as to remove the ground during the crescendo.

Prior to the time the performer commences to play, he will set the draw bars 1 to 13 in whatever fashion he considers appropriate so as to produce the type of tone coloration he feels is desirable for the particular selection. Althernatively, of course, he may accomplish the same effect by actuating one of the preselect switches connected to the panel at 24.

Now if the crescendo pedal is depressed slightly, so as to shift contact 76 from contact 76a to 76h, and simultaneously to shift contact 92 from contact 92a to 92h, any tone component which has been turned off (by positioning any one of the draw bars from 4 to 10 in the off position in contact with bus bar 34) will be shifted in the same manner as if each of these draw bars had been pulled out one step so as to be in contact with draw bar 38. This is accomplished by the connection which consists of bus bar 34, lead 214, switch blade 76, contact 761;, lead 210, switch contacts 78-78a, and lead 172 to transformer tap 132. Thus each of these tone signals is disconnected from the ground position and transferred to the first tap above ground on the transformer primary 130. Similarly, bus bar 36 is connected by way of lead 262, switch contacts 92-92b, lead 258, switch contacts 94-94a, lead 220, to transformer tap 150.

As the crescendo pedal is moved slightly further, switch contact 94 will be disconnected from contact 94a and will be connected to contact 9419, and similarly switch contact 78 will be shiftedffrom contact 78a to contact 78h. The result of this is to shift the connections of all of the tone components which are connected to bus bar 38 or bus bar 40 to the next higher bus bars; that is, bus bars 42 or 44. This shift is also accomplished with the tone components that formerly were shifted to the bus lbars 38 and 4tl by the first increment of movement of the crescendo pedal.

Note also that this shift takes place with draw bars 1, 2 and 3, provided these draw bars have been moved out away from the off position so as to be in contact with bus bar 38. This is accomplished as follows. As previously described, anything connected to bus bar 34 in the first instance has, by the first increment of movement of the crescendo pedal, been transferred to line 212 which leads to the second bus bar 38. Shifting of switch contact 78 to contact 78h therefore conveys this signal plus anything on bus bar 38 by way of line 212, contacts 78-78b to line 206, thence by way of contacts Stb-80a to lead 174 which connects with the transformer tap at 134. This action also takes place with the other connections to the transformer primaries 148 and 130, such as those from the preset panel at 24.

With successive incremental movements of the crescendo pedal, this contact shifting activity will continue until finally contact y88 is shifted from contact 88a to 88h and contact 104 is shifted from 10411 to 10411. This last shift has the effect of transferring the connections for all tone components which have been collected up to bus bars 58 and o@ to lines `184 and 232, thereby connecting tehm to the next to the highest transformer taps 144 and 162 respectively. At this juncture, therefore, the instru- Iment sounds as if all draw bars had been pulled out to the next to the loudest position, except that there may be some draw bars which are in the loudest position, these being unaffected, and except also that there may be some of the subfundamentals which are in the off position and which, as previously explained, remain off.

From the above it will be seen that regardless of the original setting of the draw ba'rs, or of the preset panel which is the equivalent thereof, movement of the crescendo pedal or other crescendo control have the effect of gradually adding to the tones originally played, all of the harmonically related or otherwise musically related tones. 'Il-his builds up the volume and also changes the nature of the tone so as to provide a sound of increasing complexity with increasing movement of the crescendo control. In the present embodiment, this .applies both to 'the arrangement which permits synthesizing tones from the various susbtantiaflly -sine waive tone components and also to the more complex tones which in the present instance have been referred to as harmonic mixtures, these tones being represented by the draw bars `11, 12 and 13. Additionally, as explained, the subfundamental, sub third harmonic, and sub fifth harmonic may or may not be used in the crescendo effect, depending upon whether the draw bars are all the way in to their off position or whether one or more of these draw Abars has been yadvanced to at ileast its first on position. One of the important considerations is that this crescendo effect can -be added to the instrument merely by the addition of the sequencing switches 74 and 90 Itogether with their control pedal or other control arrangement, plus some additional wiring, the other components in the circuit being substantially unchanged over what would normally |be available in any event. The :additional cost, therefore, of introducing the crescendo effect into the organ is relatively .small in comparison with lthe important musical effect gained thereby.

From the above description of .a preferred embodiment of my invention it will ibe appreciated that changes may be made Without departing from the spirit and scope of the invention, and that therefore the scope of the invention is to be measured by the scope of the following claims.

Having described my invention, what I claim as new and useful and desire to secure by Letters Patent is:

1. In an organ of the tone synthesizing type in which there is provided a multiplicity of sine wave tone generators according to the musical scale, a plurality of busses individual to the fundamental and various harmonics of the fundamental, playing keys adapted when played to connect Iappropriate generators to the busses so that appropriate busses have applied thereto the fundamental and various harmonics of the fundamental, an output system having a plurality of input terminals of graded effectiveness from no effectiveness to low effectiveness, to higher effectiveness, lto still higher effectiveness, land so on progressively up to high effectiveness, a plurality of controls operable to connect each of said busses individually to any selected one of said input terminals to determine the effectiveness in the output of the fundamental and various harmonics of the notes being played, and a crescendo system comprising a plurality of switches ganged together, `a control for progressively actuating switch members of said gang as said control is progressively moved, connections from said ganged switches to said input terminals such that progressive actuation of said ganged switches by their control progressively first removes the connections of whatever busses there are 'that are connected to the no effectiveness terminal and connecting these busses to the terminal of low effectiveness, next removes the bus connections from the terminal of low effectiveness and connects these busses to the terminal of higher effectiveness, next removes whatever bus connections there 4are -to said terminal of higher effectiveness 'and connects these busses to said terminal of still higher effectiveness, and so on progressively until all said bus connections have been removed from all less effective terminals and connected to said terminal of high effectiveness.

2. In an organ of the tone synthesizing type in which there is provided a multiplicity of sine wave tone generators according to the musical scale, a plurality of busses ind-ividual to the fundamental and various harmonics of |the fundamental, playing keys adapted whenl played to connect appropriate generators to the busses so that appropriate busses have -applied thereto the fundamental and various harmonics of the fundamental, an output system having a plurality of input terminals of graded effectiveness from low effectiveness, to higher effectiveness, to still higher effectiveness, and so on progressively up to high effectiveness, a plurality of controls operable to connect each of said busses individually to any selected one of said input terminals to determine the effectiveness in the output of the fundamental and various harmonics of the notes being played, and a crescendo system comprising progressively operable switching means, a control for progressively actuating said switching means as said control is progressively moved, connections from said switching means to said input terminals such that progressive actuation of said switching means progressively first switches the connections of whatever busses there are that are connected to the low effectiveness terminal to the terminal of lhigher effectiveness, next switches whatever bus connections there are to said terminal of higher effectiveness to said terminal of still higher effectiveness, and so on progressively until all said bus connections have been switched from all less effective terminals to said terminal of high effectiveness.

3. In Ian organ of the tone synthesizing type in which there is provided a multiplicity of tone generators according to the musical` scale, a plurality of busses individual to the fundamental and tones variously related to the fundamental, playing keys adapted when played to connect appropriate generators to the busses so that appropriate 'busses have applied thereto the fundamental and various of said related tones, an output system having a plurality of input terminals of graded effectiveness from low effectiveness, to higher effectiveness, to still higher effectiveness, and so on progressively up to high effectiveness, a plurality of controls operable to connect each of said busses individually to any selected one of said input terminals to determine the effectiveness in the output of the fundamental and various related tones being played, and a crescendo system comprising progressively operable switching means, a control for progressively actuating said switching means as said control -is progressively moved, connections from said switching means to said input terminals such that progressive actuation of said switching means progressively first switches the connections of whatever busses there are that are connected to the low effectiveness terminal to the terminal of higher effectiveness, next switches whatever hus connections there are to said terminal of higher effectiveness to said terminal of still higher effectiveness, and so on progressively until all said bus connections have been switched from all less effective terminals to said terminal of high effectiveness.

4. In an organ of the tone synthesizing type in which there is provided a multiplicity of sine wave tone generators according to the musical scale, a plurality of busses individual to the fundamental and various harmonics of the fundamenta-l, playing keys adapted when played to connect appropriate generators to the busses so that appropriate busses have applied thereto fundamental and various harmonics of the fundamental, an output system having a plurality of input terminals of graded effectiveness from no effectiveness to low effectiveness to higher effectiveness to still higher effectiveness and so on progressively up to high effectiveness, a plurality of controls operable to connect each of said busses individually to any selected one of said input terminals to determine the effectiveness in the output of the fundamental yand various harmonics of the notes being played, and a crescendo system comprising a plurality of single pole double throw switches ganged together, la control for sequentially actuating switch poles in said switch gang as said control is progressively moved, connections from said switches to said input terminals such that progressive actuation of said switch poles by their control first removes the connection of whatever busses there are that are connected to the no effectiveness terminal and connecting Ithese busses to the terminal of low effectiveness, next removes the bus connections from the terminal of low effectiveness and connects these busses to .the terminal of high effectiveness, next removes whatever bus connections there are to said terminals of higher effectiveness and connects these busses to said terminal of still higher effectiveness and so on progressively until all said bus connections have been removed from all less effective terminals and connected to said terminal of high effectiveness.

References Cited by the Examiner UNITED STATES PATENTS 1,77 6,821 9/ 1930 Strieby S23-43.5 X 2,227,100 12/ 1940 Manatt 84--1.27 X 2,463,597 3/ 1949 Cahill Sli-1.01 2,508,514 5/1950 Hanert et al Sli- 1.21 2,577,752 12/1951 Hanert 84-1.21 X 2,583,566 1/1952 Hanert SLi- 1.21 X 2,595,816 5/1952 Schmidt 84-1.09 X

ARTHUR GAUSS, Primary Examiner.

I. C. EDELL, Assistant Examiner. 

1. IN AN ORGAN OF THE TONE SYNTHESIZING TYPE IN WHICH THERE IS PROVIDED A MULTIPLICITY OF SINE WAVE TONE GENERATORS ACCORDING TO THE MUSICAL SCALE, A PLURALITY OF BUSSES INDIVIDUAL TO THE FUNDAMENTAL AND VARIOUS HARMONICS OF THE FUNDAMENTAL, PLAYING KEYS ADAPTED WHEN PLAYED TO CONNECT APPROPRIATE GENERATORS TO THE BUSSES SO THAT APPROPRIATE BUSSES HAVE APPLIED THERETO THE FUNDAMENTAL AND VARIOUS HARMONICS OF THE FUNDAMENTAL, AN OUTPUT SYSTEM HAVING A PLURALITY OF INPUT TERMINALS OF GRADED EFFECTIVENESS FROM NO EFFECTIVENESS TO LOW EFFECTIVENESS, TO HIGHER EFFECTIVENESS, TO STILL HIGHER EFFECTIVENESS, AND SO ON PROGRESSIVELY UP TO HIGH EFFECTIVENESS, A PLURALITY OF CONTROLS OPERABLE TO CONNECT EACH OF SAID BUSSES INDIVIDUALLY TO ANY SELECTED ONE OF SAID INPUT TERMINALS TO DETERMINE THE EFFECTIVENESS IN THE OUTPUT OF THE FUNDAMENTAL AND VARIOUS HARMONICS OF THE NOTES BEING PLAYED, AND A CRESCENDO SYSTEM COMPRISING A PLURALITY OF SWITCHES GANGED TOGETHER, A CONTROL FOR PROGRESSIVELY ACTUATING SWITCH MEMBERS OF SAID GANG AS SAID CONTROL IS PROGRESSIVELY MOVED, CONNECTIONS FROM SAID GANGED SWITCHES TO SAID INPUT TERMINALS SUCH THAT PROGRESSIVE ACTUATION OF SAID GANGED SWITCHES BY THEIR CON- 